Also, we shan't have to wait 127 years for the end of mining. You said it yourself; the reward is halved every four years. That means that it goes from 25 to 12.5 to 6.25 to 3.125 to 1.6 in just 5 halvings, or 20 years. In another 5 halvings, forty years from now, it'll be less than 0.025 BTC, which is close enough to zero that it doesn't really matter after that.
You are mistaken.
Block subsidy is issued in integer units (no decimals).
The original subsidy was 5 000 000 000 integer units (commonly referred to by the nickname "satoshi").
The current subsidy is 2 500 000 000 integer units.
In 5 halvings the subsidy will be 160 000 000 integer units.
In an additional 5 halvings (forty years from now), the subsidy will be 5 000 000 integer units. That is significantly more than 0 (by 6 orders of magnitude).
Whether those 25 mBTC will matter will depend largely on what the exchange rate of bitcoins is at the time.
If bitcoin exchange rate is $10 000 per mBTC, then 25 mBTC will be $250 000 per block.